Part A
The best inference that can be made about the man is:
He does not like to show any signs of weakness.
Part B
The sentence that best supports the answer to Part A is:
"He chuckled at his foolishness, and as he chuckled he noted the numbness creeping into the exposed fingers."
This sentence indicates that the man is aware of the dangers he faces but tries to downplay the severity of his situation. His chuckling suggests a reluctance to acknowledge his vulnerabilities.